GH-89091: raise RuntimeWarning for unawaited async generator methods (#104611)

Author: kumaraditya303

Include/internal/pycore_global_objects_fini_generated.h

@@ -269,6 +269,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(a)
         STRUCT_FOR_ID(abs_tol)
         STRUCT_FOR_ID(access)
+        STRUCT_FOR_ID(aclose)
         STRUCT_FOR_ID(add)
         STRUCT_FOR_ID(add_done_callback)
         STRUCT_FOR_ID(after_in_child)
@@ -282,7 +283,9 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(arguments)
         STRUCT_FOR_ID(argv)
         STRUCT_FOR_ID(as_integer_ratio)
+        STRUCT_FOR_ID(asend)
         STRUCT_FOR_ID(ast)
+        STRUCT_FOR_ID(athrow)
         STRUCT_FOR_ID(attribute)
         STRUCT_FOR_ID(authorizer_callback)
         STRUCT_FOR_ID(autocommit)

Include/internal/pycore_global_strings.h

@@ -22,6 +22,7 @@ extern int _PyWarnings_InitState(PyInterpreterState *interp);
 PyAPI_FUNC(PyObject*) _PyWarnings_Init(void);
 
 extern void _PyErr_WarnUnawaitedCoroutine(PyObject *coro);
+extern void _PyErr_WarnUnawaitedAgenMethod(PyAsyncGenObject *agen, PyObject *method);
 
 #ifdef __cplusplus
 }

Include/internal/pycore_runtime_init_generated.h

@@ -415,8 +415,9 @@ async def gen():
         self.assertIsInstance(g.ag_frame, types.FrameType)
         self.assertFalse(g.ag_running)
         self.assertIsInstance(g.ag_code, types.CodeType)
-
-        self.assertTrue(inspect.isawaitable(g.aclose()))
+        aclose = g.aclose()
+        self.assertTrue(inspect.isawaitable(aclose))
+        aclose.close()
 
 
 class AsyncGenAsyncioTest(unittest.TestCase):
@@ -1693,5 +1694,38 @@ async def run():
         self.loop.run_until_complete(run())
 
 
+class TestUnawaitedWarnings(unittest.TestCase):
+    def test_asend(self):
+        async def gen():
+            yield 1
+
+        msg = f"coroutine method 'asend' of '{gen.__qualname__}' was never awaited"
+        with self.assertWarnsRegex(RuntimeWarning, msg):
+            g = gen()
+            g.asend(None)
+            gc_collect()
+
+    def test_athrow(self):
+        async def gen():
+            yield 1
+
+        msg = f"coroutine method 'athrow' of '{gen.__qualname__}' was never awaited"
+        with self.assertWarnsRegex(RuntimeWarning, msg):
+            g = gen()
+            g.athrow(RuntimeError)
+            gc_collect()
+
+    def test_aclose(self):
+        async def gen():
+            yield 1
+
+        msg = f"coroutine method 'aclose' of '{gen.__qualname__}' was never awaited"
+        with self.assertWarnsRegex(RuntimeWarning, msg):
+            g = gen()
+            g.aclose()
+            gc_collect()
+
+
+
 if __name__ == "__main__":
     unittest.main()

Include/internal/pycore_unicodeobject_generated.h

@@ -0,0 +1 @@
+Raise :exc:`RuntimeWarning` for unawaited async generator methods like :meth:`~agen.asend`, :meth:`~agen.athrow` and :meth:`~agen.aclose`. Patch by Kumar Aditya.

Include/internal/pycore_warnings.h

@@ -1735,6 +1735,10 @@ async_gen_unwrap_value(PyAsyncGenObject *gen, PyObject *result)
 static void
 async_gen_asend_dealloc(PyAsyncGenASend *o)
 {
+    if (PyObject_CallFinalizerFromDealloc((PyObject *)o)) {
+        return;
+    }
+
     _PyObject_GC_UNTRACK((PyObject *)o);
     Py_CLEAR(o->ags_gen);
     Py_CLEAR(o->ags_sendval);
@@ -1839,6 +1843,13 @@ async_gen_asend_close(PyAsyncGenASend *o, PyObject *args)
     Py_RETURN_NONE;
 }
 
+static void
+async_gen_asend_finalize(PyAsyncGenASend *o)
+{
+    if (o->ags_state == AWAITABLE_STATE_INIT) {
+        _PyErr_WarnUnawaitedAgenMethod(o->ags_gen, &_Py_ID(asend));
+    }
+}
 
 static PyMethodDef async_gen_asend_methods[] = {
     {"send", (PyCFunction)async_gen_asend_send, METH_O, send_doc},
@@ -1896,6 +1907,7 @@ PyTypeObject _PyAsyncGenASend_Type = {
     0,                                          /* tp_init */
     0,                                          /* tp_alloc */
     0,                                          /* tp_new */
+    .tp_finalize = (destructor)async_gen_asend_finalize,
 };
 
 
@@ -2053,6 +2065,10 @@ _PyAsyncGenValueWrapperNew(PyThreadState *tstate, PyObject *val)
 static void
 async_gen_athrow_dealloc(PyAsyncGenAThrow *o)
 {
+    if (PyObject_CallFinalizerFromDealloc((PyObject *)o)) {
+        return;
+    }
+
     _PyObject_GC_UNTRACK((PyObject *)o);
     Py_CLEAR(o->agt_gen);
     Py_CLEAR(o->agt_args);
@@ -2256,6 +2272,15 @@ async_gen_athrow_close(PyAsyncGenAThrow *o, PyObject *args)
 }
 
 
+static void
+async_gen_athrow_finalize(PyAsyncGenAThrow *o)
+{
+    if (o->agt_state == AWAITABLE_STATE_INIT) {
+        PyObject *method = o->agt_args ? &_Py_ID(athrow) : &_Py_ID(aclose);
+        _PyErr_WarnUnawaitedAgenMethod(o->agt_gen, method);
+    }
+}
+
 static PyMethodDef async_gen_athrow_methods[] = {
     {"send", (PyCFunction)async_gen_athrow_send, METH_O, send_doc},
     {"throw", _PyCFunction_CAST(async_gen_athrow_throw),
@@ -2313,6 +2338,7 @@ PyTypeObject _PyAsyncGenAThrow_Type = {
     0,                                          /* tp_init */
     0,                                          /* tp_alloc */
     0,                                          /* tp_new */
+    .tp_finalize = (destructor)async_gen_athrow_finalize,
 };
 
 

Lib/test/test_asyncgen.py

@@ -1365,6 +1365,20 @@ PyErr_WarnExplicitFormat(PyObject *category,
     return ret;
 }
 
+void
+_PyErr_WarnUnawaitedAgenMethod(PyAsyncGenObject *agen, PyObject *method)
+{
+    PyObject *exc = PyErr_GetRaisedException();
+    if (_PyErr_WarnFormat((PyObject *)agen, PyExc_RuntimeWarning, 1,
+                          "coroutine method %R of %R was never awaited",
+                          method, agen->ag_qualname) < 0)
+    {
+        PyErr_WriteUnraisable((PyObject *)agen);
+    }
+    PyErr_SetRaisedException(exc);
+}
+
+
 void
 _PyErr_WarnUnawaitedCoroutine(PyObject *coro)
 {